"People with atrial fibrillation are at a higher risk of developing blood clots, which can cause a disabling stroke if the clots travel to the brain," Norman Stockbridge, MD, PhD, director of the FDA's division of cardiovascular and renal products, says in a news release.

Many people with atrial fibrillation take warfarin, which requires frequent monitoring with blood tests. Such monitoring is not necessary with Pradaxa.

Like other anti-clotting drugs, however, Pradaxa can have adverse effects, including life-threatening bleeding. Other side effects may include gastrointestinal symptoms (including dyspepsia, an unpleasant feeling in the stomach), stomach pain, nausea, heartburn, and bloating.

The drug will be distributed with a medication guide explaining the risk of serious bleeding. Patients will get a copy of the guide every time they fill or refill a Pradaxa prescription.

Pradaxa's generic name is dabigatran etexilate. It is made by Boehringer Ingelheim Pharmaceuticals.